# XO0411: two fields have one wire key

A field's key in `derive Json` and its column in `derive SqlRow` is its wire name (`kind as "type": Str`), else its name under the derive's `case:` rule, else its name. Two fields of one struct with the same key would read the same JSON key or column. Give one of them another wire name. See core 2.2.

## Example

```xo
struct Event {
  kind: Str
  other as "kind": Str
} derive Json
```

## Fix

```xo
struct Event {
  kind: Str
  other as "other_kind": Str
} derive Json
```

Run `xo explain XO0411` for this text in a terminal, or see
[section 10.6 of the specification](../../spec/core/#106-diagnostic-codes).